Indoor Secondary Organic Aerosol Formation Initiated from Reactions between Ozone and Surface-Sorbed d‑Limonene

2013-06-18T00:00:00Z (GMT) by Michael S. Waring Jeffrey A. Siegel
Reactions between ozone and terpenoids produce numerous products, some of which may form secondary organic aerosol (SOA). This work investigated the contribution to gas-phase SOA formation of ozone reactions with surface-sorbed d-limonene, which is common indoors. A model framework was developed to predict SOA mass formation because of ozone/terpenoid surface reactions, and it was used with steady state experiments in a 283 L chamber to determine the aerosol mass fraction of SOA resulting from surface reactions, ξ<sub>s</sub> (the ratio of mass of SOA formed and mass of ozone consumed by ozone/terpenoid surface reactions), for ozone/d-limonene reactions on stainless steel. The ξ<sub>s</sub> = 0.70–0.91, with lower relative humidity leading to both higher mass and number formation. Also, surface reactions promoted nucleation more than gas-phase reactions, and number formation due to surface reactions and gas-phase reactions were 126–339 and 51.1–60.2 no./cm<sup>3</sup> per μg/m<sup>3</sup> of formed SOA, respectively. We also used the model framework to predict that indoor spaces in which ozone/d-limonene surface reactions would likely lead to meaningful gas-phase SOA formation are those with surfaces that have low original reactivity with ozone, such as glass, sealed materials, or smooth metals.